Inhalation device

ABSTRACT

An inhalation device is described for use with a medicament pack in which at least one container for medicament in powder form is defined between two sheets peelably secured to one another. The device comprises means for peeling the sheets apart at an opening station to open the container; and an outlet, communicating with the opened container, through which a user can inhale medicament in powder form from the opened container.

FIELD AND BACKGROUND OF THE INVENTION

[0001] This invention relates to an inhalation device by means of whicha user can inhale medicament in the form of a powder.

[0002] Inhalation devices are known for use with blister packs in whichthe medicament is held in powder form in the blisters thereof. Suchdevices include a puncturing member which punctures each blister inturn, thus enabling the medicament to be inhaled therefrom. It is anobject of the present invention to provide an inhalation device thedesign of which has the potential, if desired, to handle a medicamentpack having a large number of discrete unit doses, without the devicebecoming unacceptably large.

BRIEF SUMMARY OF THE INVENTION

[0003] According to the present invention there is provided aninhalation device for use with a medicament pack in which at least onecontainer for medicament in powder form is defined between two memberspeelably secured to one another, the device comprising means defining anopening station for the said at least one container; means for peelingthe members apart at the opening station to open the container; and anoutlet, communicating with the opened container, through which a usercan inhale medicament in powder form from the opened container.

[0004] Preferably the medicament pack is formed from two elongate sheetswhich define a plurality of medicament containers spaced along thelength thereof, means being provided for indexing each container in turnto the opening station.

[0005] The invention also provides a medicament pack for use in aninhalation device, the pack comprising an elongate strip formed from abase sheet having a plurality of recesses spaced along its length and alid sheet hermetically but peelably sealed thereto to define a pluralityof containers, each container having therein inhalable medicament inpowder form. The strip is preferably sufficiently flexible to be woundinto a roll.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a rear view of a first embodiment of the invention;

[0007]FIG. 2 is an axonometric exploded view of the components of theembodiment of FIG. 1;

[0008]FIGS. 3a, 3 b and 3 c are an axonometric view, a longitudinalsection and an end view (partly broken away) showing a clutch used inthe embodiment of FIGS. 1 and 2;

[0009]FIGS. 4a and 4 b are an axial section and cross-sectionrespectively, on a larger scale than FIGS. 1 and 2, of a mouthpiecewhich may be used in the first embodiment (or in some other embodiment);

[0010]FIG. 5 is a front view of a second embodiment, with a coverthereof removed to show the interior;

[0011]FIG. 6 is a rear view of the second embodiment, but showing theinterior thereof

[0012]FIG. 7 is an axonometric front view of the second embodiment;

[0013]FIG. 8 is an axonometric rear view of the second embodiment;

[0014]FIG. 9 is an axonometric exploded view of the second embodiment;

[0015]FIG. 10 is a front view of a third embodiment, showing theinterior structure thereof;

[0016]FIG. 11 is an axial view, on a larger scale, showing themouthpiece of the third embodiment;

[0017]FIG. 12 is a view from below of the third embodiment;

[0018] FIGS. 13 to 16 show a fourth embodiment of the invention, FIG. 13being an underplan view, FIG. 14 a section on line A-A in FIG. 13, FIG.15 a section on line B-B in FIG. 13, and FIG. 16 an exploded view on asmaller scale;

[0019]FIGS. 16a to 16 d show the fourth embodiment in successive stagesof operation, and FIG. 16e is a section taken on line A-A in FIG. 16a;

[0020] FIGS. 17 to 20 show a fifth embodiment of the invention, FIG. 17being an end view, FIG. 18 a section on line A-A in FIG. 17, FIG. 19 asection on line B-B in FIG. 17, and FIG. 20 an exploded view;

[0021] FIGS. 21 to 24 show a sixth embodiment of the invention, FIG. 21being an end view, FIG. 22 a section on line A-A in FIG. 21, FIG. 23 asection on line B-B in FIG. 21, and FIG. 24 an exploded view;

[0022] FIGS. 25 to 29 show a modified clutch which may be used in thoseembodiments of the invention which require it, and are, respectively, afront view, a top view, a back view, a left side view and an axonometricview;

[0023]FIG. 30 is an exploded perspective view showing a furtherembodiment of clutch which may be used;

[0024]FIG. 31 is an exploded perspective view of yet another embodimentof clutch which may be used;

[0025]FIG. 31a is transverse section through the clutch shown in FIG.31;

[0026] FIGS. 32 to 34 show successive positions of operation of anotherembodiment of the invention, in rear view; and

[0027]FIG. 35 is a perspective view on a larger scale showing anembodiment of medicament pack according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0028] Referring now to FIGS. 1, 2 and 3 a to 3 c, these show aninhalation device in which is mounted a flexible strip 1 defining aplurality of pockets 2 each of which contains a dose of medicament whichcan be inhaled, in the form of a powder. The strip 1 comprises a basesheet 3 in which blisters are formed to define the pockets 2, and a lidsheet 4 which is hermetically sealed to the base sheet 3 except in theregion of the blisters, in such a manner that the lid sheet and the basesheet can be peeled apart. The sheets are sealed to one another overtheir whole width except for leading end portions thereof where they arepreferably not sealed to one another at all. The lid and base sheets areeach preferably formed of a plastics/aluminium laminate, and the lid andbase sheets are preferably adhered to one another by heat sealing. Byway of example, the lid material may be a laminate consisting of 50 gsmbleach kraftpaper/12 micron polyester (PETP) film/20 micron soft temperaluminium foil/9 gsm vinylic peelable heat seal lacquer (sealable toPVC), and the base material may be a laminate consisting of 100 micronPVC/45 micron soft temper aluminium foil/25 micron orientated polyamide.The lacquer of the lid material is sealed to the PVC layer of the basematerial to provide the peelable seal between the lid and base sheets.

[0029] The strip 1 is shown as having elongate pockets which runtransversely with respect to the length of the strip. This is convenientin that it enables a large number of pockets to be provided in a givenstrip length. The strip may, for example, be provided with sixty or onehundred pockets, but it will be understood that the strip may have anysuitable number of pockets.

[0030] The inhalation device comprises a body 10 defining three storagechambers, namely a chamber 11 in which the strip 1 is initially housedand from which it is dispensed, a chamber 12 for receiving the usedportion of the base sheet 3, and a chamber 13 within which the usedportion of the lid sheet can be wound up on a wheel 14. The chambers 11and 12 contain respective curved leaf springs 28 and 29, the purpose ofwhich is described below. The body defines a further chamber 15 whichhouses an index wheel 16. This has a plurality of grooves 17 extendingparallel to the axis of the wheel 16. The grooves are spaced at a pitchwhich is equal to the distance between the centre lines of adjacentpockets 2. The chambers 11, 12, 13 and 15 are closed by a lid 30. Thechamber 15 communicates with the chambers 11, 12 and 13 via passages 31,33 and 32 respectively.

[0031] The chamber 15 communicates via a slit 18 which, in turn, extendsupwardly within a mouthpiece 20. The slot 18 also communicates with airinlets, as will be described below with reference to the specificmouthpiece shown in FIGS. 4a and 4 b. The mouthpiece 20 is provided withadditional air inlets 21 shown here in the form of a pair of circularapertures, though they may be of some other shape, as they are in FIGS.4a and 4 b. The primary purpose of the additional air inlets 21 is toprovide additional air to the user and thus reduce the resistance toinhalation, though they may serve one or more additional purposes, asthey do in FIG. 4a and 4 b and as is described below with reference tothose Figures.

[0032] A means is provided by which the user can rotate the index wheeland the lid wheel in steps of a predetermined size. This means comprisesa ratchet wheel 22 and a gear wheel 23, both connected to rotate inunison with the index wheel 16, a lever 24 arranged to rotate about thesame axis as the ratchet wheel 22 and gear wheel 23, but independentlythereof, and a gear wheel 25 which meshes with the gear wheel 23 and isarranged to rotate the lid wheel 14. The lever 24 carries a pusher arm26, the end of which is arranged to engage the teeth of the ratchetwheel 22. The teeth of the ratchet wheel are also engaged by a pawl 27fixedly secured to the body 10. For reasons which will become apparentfrom the description below of the operation of this embodiment, the gearwheel 25 is not connected directly to the lid wheel 14, but is connectedvia a slipping clutch 50 which is housed within the lid wheel 14. Theeffect of the provision of this clutch is that slipping occurs betweenthe lid wheel and the gear wheel 25 when the force required to rotatethe lid wheel exceeds a predetermined amount.

[0033] The clutch 50 comprises a disc 51 provided with radiallyextending serrations 52, or other surface roughness, which is held inengagement with a similarly serrated or roughened surface 53 provided onan end face of the lid wheel 14 by a compression spring 54. The spring54 bears at one end against an inwardly directed surface 55 of the lidwheel and at the other end against a nut 56 threaded on a bolt 57.

[0034] The device described above can be made so as to be reusable afterthe doses of medicament contained in the pockets 2 have all beendispensed. In that case, provision can be made for the user to gainaccess to the interior of the device, for example by removing the lid30, so as to insert therein a fresh strip 1, for example in a cassette.Alternatively, however, the device may be made to be disposable once thestrip 1 with which it is supplied has been used up.

[0035] In either event, when the device is first used the bulk of thestrip 1 is within the chamber 11, kept in a relatively tight reel by theleaf spring 28, with a short portion at the leading end thereof passingout of the chamber 11 through the passage 31 to the index wheel 16. Theforemost part of the leading end of the strip is peeled apart so thatthe leading end of the lid sheet 4 can be secured to the lid wheel 14,and so that the leading end of the base sheet 3 can enter the passage33. The end of the lid sheet 4 is held in place on the lid wheel 14 bymeans of a key 34 which is a force fit in a slot 35 in the wheel 14.

[0036] A user desiring to use the device pushes the lever 24 in ananticlockwise direction, as viewed in FIG. 1, so that the pusher arm 26urges the ratchet wheel 22 through an angle equal to the angulardistance between two adjacent teeth. This causes the ratchet wheel 16 torotate by an angular amount equal to the pitch of the groove 17 thereofand thus equal to the distance between two adjacent pockets 2 in thestrip 1.

[0037] This brings a pocket 2 opposite the slot 18 in the body 10. Sincethe ratchet wheel 22 and gear wheel 23 move in unison, and since thegear wheel 25 meshes with the gear wheel 23, movement of the lever 24also causes the lid wheel 14 to rotate. This peels a sufficient portionof the lid sheet 4 away from the base sheet 3 to expose the contents ofthe pocket 2 which is being brought into alignment with the slot 18.

[0038] When the user inhales through the mouthpiece 20 the flow of airwhich this produces entrains powder from the opened pocket, so that thepowder is inhaled by the user. One way in which this can occur isexplained in more detail below with reference to the embodiment ofmouthpiece shown in FIGS. 4a and 4 b. Each time the above procedure isrepeated a further length of lid sheet is wrapped around the lid wheel14 and a further length of base sheet enters chamber 12 through passage33. The leaf spring 29 therein ensures that the base sheet is coiled upand does not snag on the wall of the chamber 12.

[0039] One effect of winding up the lid sheet on the lid wheel 14 isthat the external diameter of the wheel plus the sheet wound thereongradually increases. Were it not for the use of a slipping clutch toconnect the gear wheel 25 to the lid wheel 14 this would have the resultthat successive operations of the lever 24 would try to cause aprogressively longer length of lid sheet to be wound on to the lidwheel. The slipping clutch 50, however, avoids this effect, the clutchslipping each time by an amount sufficient to ensure that for everyoperation of the lever the amount of lid sheet wound on is preciselyequal to the pitch of the pockets 2.

[0040]FIGS. 4a and 4 b show a portion of the index wheel 16 with apocket 2 therein, in conjunction with a mouthpiece which differsslightly from the mouthpiece 20 shown in FIGS. 1 to 3, and which isdenoted by reference numeral 120. The mouthpiece 120 has air inlets 140,to which reference in general terms has already been made in connectionwith FIGS. 1 to 3, and a central powder outlet 119, one end of which isopen to the pocket 2 and the other end of which opens into the interiorof the mouthpiece 120.

[0041] When a user inhales through the mouthpiece 120 this causes air toflow in through the inlets 140 and thence through the pocket 2, into thepowder outlet 119, and out through the mouthpiece 120. By thus directingthe flow of air through the pocket 2, efficient entrainment of powder inthe airflow is achieved, with consequent efficient emptying of thepocket. The mouthpiece 120 is provided with additional air inlets 121,shown here by way of example as being four in number, which opentangentially into the mouthpiece. When the user inhales air is drawninto the mouthpiece not only through the air inlets 140 but also throughthe air inlets 121, and the air entering through the inlets 121 producesa swirling airflow which helps to distribute powder effectively withinthe airflow and reduce the extent to which powder is deposited on theinside of the mouthpiece. This also helps to break up any aggregates ofpowder which may be present in the blister.

[0042] An alternative clutch arrangement is shown in FIGS. 25 to 29. Inthis, the index wheel 16 and the lid wheel 14 have respective toothedgear wheels 63 and 64 secured to them for rotation therewith. Thedirection of rotation is indicated by arrows in FIG. 27.

[0043] Gear wheel 63 has a toothed surface 65, with the teeth beingprovided continuously all the way round the surface 65 and at a constantpitch. By contrast, the gear wheel 64 has a toothed surface 66 fromwhich some teeth are missing by virtue of the provision of radiallyextending slots 67. The circumferential width of each slot at thesurface 66 is equal to one tooth pitch. The drawings show three suchslots, but it should be understood that there could instead be one slot,two slots, or more than three slots. To one side of each of the slots67, in fact upstream of each slot as considered in the direction ofrotation of the gear wheel 64, a toothed section 68 is defined betweenthe slot 67, and a narrow slit 69. The radially inner end of each slit69 communicates with an aperture 70, so that each toothed portion 68 isconnected to the remainder of the gear wheel 64 only by an arm 71. Thegear wheel 64, or at least those portions thereof which provide the arms71, is made of a material which permits the toothed portions 68 to flexresiliently back and forth in a circumferential direction. The restposition of the portions 68 is as shown in the drawings, but when aforce is applied to a portion 68 in the direction of rotation of thegear wheel 64, the portion 68 can move so as to close the gap 67 at theradially outer end. This has the effect that a tooth is then “missing”not at the end of the slot 67 but at the end of the slit 69.

[0044] When the circumferential force applied by the gear wheel 63 tothe gear wheel 64 is below a predetermined level the toothed portions 68remain in their rest positions and the gear wheel 64 behaves just as ifit had a continuous toothed surface like that of gear wheel 63. However,if the load exceeds a predetermined value, each time a toothed section68 meshes with the gear wheel 63 it is moved circumferentially to closeup the slot 67 at its outer end and open the slit 69. This movement ofthe toothed section 68 by a distance equal to the tooth pitch has theeffect of producing slippage of the gear wheel 64 with respect to thegear wheel 69 equal to one tooth pitch. In this way, the illustratedarrangement is able to permit a total slippage of the gear wheels withrespect to one another by a maximum of a distance equal to three timesthe tooth pitch per revolution, and hence a corresponding slippage ofthe lid wheel and index wheel with respect to one another. As will beappreciated, providing more or fewer toothed sections than the threeillustrated will permit more or less than this maximum slippage.

[0045] A second embodiment of the inhalation device according to theinvention is shown in FIGS. 5 to 9. This is intended for use with astrip 201, similar to the strip 1 used in the first embodiment except asregards the spacing of the pockets (for which see below). In manyrespects the second embodiment resembles the first embodiment, andcomponents in the second embodiment which correspond in general terms toparticular components in the first embodiment are denoted by the samereference numerals, but with the addition of 200. The main differencebetween the first embodiment and the second embodiment is that in thelatter there is no index wheel corresponding to the index wheel 16 ofthe first embodiment. Instead, indexing of the strip 1, to ensure thateach operation of the lever advances the strip by an amount equal to thepitch of the pockets, is achieved by a resiliently flexible arm 250terminating in a tooth 252 which engages between adjacent pockets. Eachtime the lever 224 is operated the arm 250 is resiliently depressed as apocket slides past the tooth 252 thereof, and the tooth then springsback into engagement with the strip to the rear of the pocket which hasjust passed it.

[0046] It will be appreciated that, as in the case of the firstembodiment, the diameter of the lid wheel 214 with the lid sheet thereongradually increases during operation. Since a slipping clutch cannot beused in this embodiment the effect just described is 73 compensated byhaving the spacing of the pockets 2 gradually increasing towards therear end of the strip.

[0047] One other difference which will be noted between the first andsecond embodiments, is that in the latter the chambers 211 and 212 forma single composite chamber, unlike the separate chambers 11 and 12 inthe first embodiment. However, this need not be so, and the firstembodiment could use a single composite chamber and the secondembodiment could use separate chambers.

[0048] FIGS. 10 to 12 show a third embodiment. In many respects thisresembles the second embodiment, and components in the third embodimentwhich correspond in general terms to components in the second embodimentare denoted by the same reference numerals but with the addition of afurther 100.

[0049] One difference which will be observed between the second andthird embodiments is that in place of the lid wheel 114 a pair of wheels314 a and 314 b are employed, with the lid sheet being gripped in thenip between the wheels 314 a and 314 b, which act as a mangle. Thesewheels are knurled or otherwise roughened to improve the grip betweenthe wheels and the lid sheet. The used lid sheet is not wound up but isfed into a chamber 313, so that no problem arises, as it does in thefirst two embodiments, with the lid wheel attempting to wind upprogressively longer lengths of lid as operation of the devicecontinues.

[0050]FIG. 11 shows the mouthpiece to be of a somewhat different designto that shown in FIGS. 4a and 4 b. The mouthpiece is shown as having asingle air inlet 340 in place of the pair of air inlets 140, and thepowder outlet 119 of FIGS. 4a and 4 b is replaced by a mouthpieceportion 319 of reduced width. It should be understood, however, that thedevice shown in FIGS. 10 to 12 could be modified so as to incorporate amouthpiece more closely resembling FIGS. 4a and 4 b.

[0051]FIG. 10 shows the device as being provided with a hinged cover360, and such cover could be provided for either of the first twoembodiments. FIG. 12 shows the device as having a window 370 throughwhich indicia on the strip can be viewed. By printing the strip withnumbers or other indicia which correlate with the number of pockets fromwhich powder has been dispensed, or alternatively is to be dispensed,the user is provided with an indication of how many doses have been usedor, alternatively, how many doses remain. Another possibility is to usea dose counting device driven by one of the rotating components of theinhalation device. It should be noted that similar indicia and means forviewing those indicia could be provided in all the embodiments;

[0052] FIGS. 13 to 16 show a further embodiment of the invention. Thisis similar in the principle of its operation to the first embodiment,and components in the fourth embodiment which correspond in generalterms to components in the first embodiment are denoted by the samereference numerals but with the addition of 400.

[0053] As in the first embodiment, the device receives a flexible strip,here denoted as 401, comprising a base sheet 403 in which pockets 402are defined and a lid sheet 404. The strip 401, is shown most clearly inFIG. 35. The lid sheet 404 has a loop 404 a formed at the leading endthereof for engagement over a post 471 a extending upwardly from atoothed wheel 471 (described below). The base sheet has a lead portion403 a of reduced width for engagement in a slot 470 a formed in the basewinding wheel 470 (described below). The leading end portions of thebase sheet and lid sheet are not sealed together, as can be seen in FIG.35.

[0054] The body 410 comprises a base 410 a and a top 410 b both ofgenerally circular shape. When the device is assembled the base and topare snap-fitted together. The body defines a single internal chamberwithin which the strip 401 is housed and within which are also housed awheel 414 for winding up the used portion of the lid sheet 404, a basewinding wheel 470 and an index wheel 416. The index wheel 416 is hollowand an index ratchet wheel 422 is housed within it. All the wheels justmentioned are mounted in the chamber defined by the body, for rotationalmovement with respect thereto. A pawl 470 b is attached to the body 410and engages the teeth of the base winding wheel 470 to prevent the wheelmoving anticlockwise, thus ensuring that the strip 401 can only proceedforwards through the device.

[0055] The lid winding wheel 414 is formed in two parts, namely atoothed wheel 471 having teeth 472 and a shaft 473, and a collapsiblewheel 474 having a hollow central shaft 475 and a plurality of resilientarms 476, for example, as shown, eight such arms, extending from thecentral shaft 475 each at an angle to a radius. The toothed wheel 471has a lug 477 which engages in a corresponding notch in the shaft 475 sothat the wheels 471 and 474 rotate in unison.

[0056] The hollow index wheel 416 has external teeth 478 which mesh withthe teeth of the base winding wheel 470 and the teeth of the wheel 471.Ratchet teeth 479 are formed on the internal walls of the index wheel416, and the index ratchet wheel 422 has two pawls 480 which engage theratchet teeth 479.

[0057] The device further comprises a lever 424 which comprises anarcuate wall 481 with a finger tab 482, and an arm 483 which extendsinwardly from the wall 481 and carries an arcuate array of teeth 484 atits distal end. The lever is pivotally mounted to the centre of the base410 a for movement about an axis which is at the centre of the pitchcircle of the teeth 484, the teeth 484 mesh with the teeth 485 on theindex ratchet wheel 422.

[0058] A manifold 486 provides communication between the chamber withinthe body 410 and a mouthpiece 420. The manifold has a powder outlet 419and also has a passageway 487 to allow used lid strip 404 to pass to thecollapsible wheel 474. Optionally, a roller 488 may be provided to guidethe strip 404 into the passageway 487.

[0059] A dose monitor ring 489 having teeth 490 is arranged to berotatable within the body base 410 a. On its lower surface this bearsindicia (not visible in the drawings) which can be viewed by the userthrough a window 494 in the body 410. It will be noted from FIGS. 16a to16 d that the window can be seen both when the cover 491 (see below) isclosed and when it is open. The indicia indicate either exactly orapproximately the number of doses left (or the number of doses used, ifpreferred). The ring 489 is rotated by virtue of the fact that its teeth490 are engaged by the teeth 478 of the index wheel.

[0060] The device is provided under a cover 491 which is pivotallymounted on the body 410 by means of a lug 492 on the body top 410 b anda corresponding lug 493 on the body base 410 a. The cover is pivotalbetween an open position (shown in FIG. 14) in which the mouthpiece isexposed and a closed position in which it is not, as is described morefully below.

[0061] In operation, the user moves the cover 491 to its open positionand then presses on the finger tab 482 of the lever 424 to cause it tomove as the lever pivots. This makes the index ratchet wheel 422 rotatewhich, via the pawls 480, causes the index wheel 416 also to rotate.Rotation of the index wheel 416 produces rotation of both the basewinding wheel 470 and the lid winding wheel 414, thus peeling the basesheet and lid sheet apart over a distance sufficient to expose apreviously unopened pocket 402 opposite the end of the powder outlet 419in the manifold 486. The patient can then inhale through the mouthpiece,as in the preceding embodiments.

[0062] Successive stages in the operation of the device are shown inFIGS. 16a to 16 d. The device is in its closed position in FIG. 16a. Thefinger tab 482 of the lever 424 is at this stage in a recess 482 bformed in the body 410 (seen more clearly in FIGS. 16b and 16 c). Thecover 419 is held stationary as the body 410 is rotated anticlockwise, arecess 410 c being provided in the periphery of the body to enable theuser to insert a finger for this purpose. The device is thus moved tothe partly open position shown in FIG. 16b. During this process thelever 424 remains stationary with respect to the cover 491. This isachieved by the lever being provided internally with a resilient arm 424a the tip 424 b of which engages in a recess 491 a in the cover 491. Thearm 424 a is attached to the lever 424 via a cylindrical member 424 c.As viewed in FIG. 16a, the arm 424 a extends anticlockwise from themember 424 c over an arc of about 90°. The cylindrical member 424 c isguided in an arcuate slot 410 d formed in the body 410. The slot 410 dextends through an arc of about 180°, and in FIG. 16a the member 424 cis shown as being approximately half way along its length. In FIG. 16bit is shown as being at one end.

[0063] The user continues to rotate the body 410 from the position shownin FIG. 16b to the position shown in FIG. 16c. During this furtherrotation tip 424 b of the arm 424 a jumps out of the recess 491 a. Thisoccurs because, with the member 424 c at one end of the slot 410 d,movement of the body 410 carries the member 424 c with it in ananticlockwise direction and hence compels the arm 424 a likewise to moveanticlockwise. The user then moves the lever 424 by pushing on thefinger tab 482 to cause it to rotate anticlockwise through the positionshown in FIG. 16c to the position shown in FIG. 16d where the finger tab482 re-enters the recess 482 b. The steps thus far described both exposethe mouthpiece 420 and open a fresh blister. The device is therefore nowready for the user to inhale.

[0064] After use, the body 410 is rotated clockwise, the lever 424moving in unison with the body, to bring the device back to the positionof FIG. 16a.

[0065] It will be noted that the collapsible wheel 474 in effect assumesthe function of the clutch in the first embodiment. As more lid sheet iswound onto the wheel 474 the arms 476 gradually flex inwardly, and theeffect is to keep the external diameter of the reel of wound up lidsheet substantially constant, while the internal diameter thereofgradually decreases.

[0066] Instead of the wheel 414 with its collapsible wheel 474 it ispossible to use the alternative structure shown in FIG. 30 or that shownin FIGS. 31 and 31a. The principle of operation of the structure shownin FIG. 30 is very similar to that of the clutch arrangement shown inFIGS. 25 to 29. The structure of FIG. 30 comprises two components 800and 801. The component 800 comprises a generally cylindrical hollowhousing 802 open at its lower end and three arcuate arrays of teeth 803.The cylinder 802 has a slot 804 extending through the upper surfacethereof, and a post 805 for receiving the leading end of the lid sheet.The component 801 comprises a disc 806 provided with three arcuatearrays of teeth 807, and an upright member 808 extending upwardly fromthe disc 806. The member 808 is formed of a material, example a plasticsmaterial, which is resilient in torsion.

[0067] The two components 800 and 801 are snap-fitted together so thatthe upper end of the member 808 is received in the slot 804 and cannotrotate with respect thereto. The arrays of teeth 803 and 807 arecoplanar and alternate with one another. The teeth 803 and 807 mesh withthe teeth 478 of the index wheel. Each array 807 is separated from oneof the adjacent arrays 803 (but not from the other) by a gap equal toone tooth. Thus, there are three gaps, each of one tooth width, aroundthe assembled arrays. Because the member 808 can flex in torsion, thedisc 806 is free to move back and forth between a position in which thegaps are each on one side of a respective array 807 and a position inwhich the gaps are each on the other side of a respective array 807.This has the effect of producing slippage of the structure shown in FIG.30 with respect to the index wheel.

[0068] The structure shown in FIG. 31 is a slipping clutch. It comprisestwo components 810 and 811, snap-fitted together. The component 810comprises a generally cylindrical housing 812 open at its lower end andhaving a post 813 for receiving the leading end of the lid sheet. Theinterior of the housing 812 is provided with longitudinally extendingserrations 814, as can be seen in FIG. 31a. The component 811 comprisesa cylinder 815 which extends upwardly from a disc 816 provided withteeth 817. The teeth 817 mesh with the teeth 478 of the index wheel. Thecylinder 815 is provided on its outer surface with a pair of pips 818which are in interfering engagement with the serrations 814. When therotational force applied by the component 811 to the component 810 isbelow a predetermined level the components rotate together. However, thecylinder is made of a material, for example a plastics material, whichcan deform radially, and when the rotational force exceeds thepredetermined level such deformation takes place, permitting the pips818 to move over the serrations 814.

[0069] Although in the embodiment of FIGS. 13 to 16, with or without themodifications of FIGS. 30 and 31, the base sheet is wound up as well asthe lid sheet, it is not necessary for there also to be a slippingclutch or the like between the index wheel and the base winding wheel.The diameter of the base winding wheel is so chosen that initially thebase sheet is wound up only very loosely, and the tightness with whichthe sheet is wound increases during operation but without ever reachingan unacceptable level. In theory, the base sheet could be wound upprecisely via a slipping clutch or the like, with the lid sheet beingonly loosely wound, but in practice it is much easier to wind up the lidprecisely because it is flat and because it is thinner than the basesheet.

[0070] FIGS. 17 to 20 show in diagrammatic form the main operative partsof a device which has some similarities to those shown in FIGS. 10 to12, i.e. it is a mangle device. However, it is to be understood thatFIGS. 17 to 20 do not show a complete device, the chamber for the unusedstrip and the used base material being omitted. Components in thisembodiment which correspond in general terms to particular components inthe embodiment of FIGS. 10 to 12 are denoted by the same referencenumerals, but with the addition of a further 200.

[0071] The device of FIGS. 17 to 20 comprises a pair of wheels 514 a and514 b which have meshing teeth formed thereon and which act as a mangleengaging the used lid material. This material is fed into a chamber 513.The wheel 514 b is an idler wheel and is urged into engagement with thewheel 514 a by a compression spring 595 which acts on a carrier 596which carries the wheel 514 b. The wheel 514a has a ring of gear teeth598 which mesh with teeth 597 formed on an index wheel 516 whichperforms the same indexing function as the index wheel 16 in the firstembodiment and is rotatable in a chamber 515. The chambers are formed ina body 510 and lids 530 a and 530 b are secured to opposite sides of thechamber. Inhalation is through a mouthpiece 520. The device is operatedby a lever 524 which turns the index wheel 516 via a pusher arm 526.

[0072] The embodiment shown in FIGS. 21 to 24 is another type of mangledevice, but one in which both the lid and base sheets pass through thewheels of the mangle.

[0073] The embodiment of FIGS. 21 to 24 comprises a body 610 defining asubstantially circular chamber 611 and having lids 612 a and 612 bsecured thereto. Within the chamber 611 an index wheel 613 and a baseand lid winding wheel 614 are rotatably mounted, the wheels 613 and 614having gear teeth which mesh with one another. The index wheel 613 hasgrooves 615, and a lid gripper wheel 618, rotatably carried in a carrier619 is also mounted adjacent the grooves 615, downstream of the manifold616. A roller 620 is mounted behind the manifold 616 to guide the lidsheet.

[0074] Flexible strip 601 is provided in the chamber 611, the main partof the strip being initially coiled up around the internal wall of thechamber. The leading end of the strip passes between guide members 622and 623 over part of the circumference of the index wheel 613, with thepowder containing pockets thereof engaged in the grooves 615. At thepoint where the strip meets the manifold 616 it is peeled apart, and thelid sheet passes behind the manifold and over the roller 620 while thebase sheet passes between the index wheel and the manifold. After themanifold both sheets pass between the index wheel and the lid gripperwheel 618, and are gripped thereby. The front end of the strip is fixedin the base and lid winding wheel 614.

[0075] In use, the strip 601 is advanced by rotating the index wheel, bymeans of a lever 624, via a pusher arm 626, which causes correspondingrotation of the base and lid winding wheel. This winds up the base andlid, initially loosely, though increasing in tightness as the operationproceeds, but without, however, the tightness ever reaching anunacceptable level. The lid and base sheets are peeled apart where thestrip meets the manifold 616, presenting a fresh pocket of powder to thepowder outlet 617. Inhalation is via a mouthpiece 620.

[0076] FIGS. 32 to 34 show an embodiment of the invention incorporating,as a further feature, indicia which instruct the user as to thesuccessive steps which the user is to take to operate the device. Apartfrom the indicia, the device is largely the same as the embodiment shownin FIGS. 1 to 3, and the same reference numerals are used for thecorresponding components. However, there are some additional components,as will be apparent from the following description.

[0077] The device shown in FIGS. 32 to 34 has a cover 700 which ispivotally connected to the remainder of the device for pivotal movementabout an axis 701. The gear wheels 23 and 25 and the associatedcomponents are covered by a rear wall 702. This extends over the wholeof the rear of the device, but in the drawings all except a smallportion thereof is shown broken away for ease of understanding. Thelever 24 is provided with an arcuate extension 703, on an edge whereofis formed a cam 704. The extension 703 carries indicia in the form ofinstructions to the user, in this case the legends “OPEN COVER”, “PRESSBUTTON”, “INHALE”. When the lever 24, and hence the extension 703, arein particular positions a respective one of these legends is visiblethrough a window 705 in the rear wall 702. The distal end of theextension 703 constitutes a button 706. The end of the lever 24 remotefrom the extension 703 carries a tongue 707 pivotal therewith.

[0078]FIG. 32 shows the device in its rest position. The legend “OPENCOVER” is visible through the window 705. If a patient now opens thecover 700 this brings the device into the position shown in FIG. 33. Itwill be seen that the top rear edge of the cover has struck the cam 704and moved the extension 703 through an angle such as to make the legend“PRESS BUTTON” visible through the window 705. If the user now pressesthe button 706 this causes the lever 24 to rotate, thus opening apowder-containing container, as described in connection with FIGS. 1 to3. This brings the device into the position shown in FIG. 34, in whichthe legend “INHALE” is visible through the window 705. It will also beseen that in the position of FIG. 34 the tongue 707 protrudes upwardly.Accordingly, when the user, having inhaled, closes the cover, the tongue707 is struck by a lug 708 on the underside of the cover, which pushesthe lever 24, with its extension 703, back into the position shown inFIG. 32, once again causing the legend “OPEN COVER” to be displayed.

[0079] The device just described not only gives the step-by-stepinstructions to the user, thus reducing the risk of a patient beingconfused, but also makes it difficult for the patient to use the deviceother than in the intended manner, by virtue of the fact that the button706, once depressed, is not again accessible until the user closes thecover and reopens it.

[0080] In the embodiments described above, reference is made to amouthpiece. However, if the device was to be used for purposes otherthan oral inhalation some other outlet would be employed, e.g. anosepiece.

1. An inhalation device for use with a medicament pack in which at leastone container for medicament in powder form is defined between twomembers peelably secured to one another, the device comprising meansdefining an opening station for the said at least one container; meansfor peeling the members apart at the opening station to open thecontainer; and an outlet, communicating with the opened container,through which a user can inhale medicament in powder form from theopened container.
 2. A device according to claim 1, adapted for usewhere the said two members are two sheets.
 3. A device according toclaim 2, adapted for use where the sheets are elongate sheets whichdefine a plurality of medicament containers spaced along the lengththereof, the device being provided with indexing means for indexing eachcontainer in turn in communication with the outlet.
 4. A deviceaccording to claim 3, adapted for use where one of the sheets is a basesheet having a plurality of pockets therein, and the other of the sheetsis a lid sheet, each pocket and the adjacent part of the lid sheetdefining a respective one of the containers, the device comprisingdriving means for pulling the lid sheet and base sheet apart at theopening station.
 5. A device according to claim 4, wherein the saiddriving means comprises lid driving means for pulling the lid sheet. 6.A device according to claim 5, comprising a rotatable index wheel havingrecesses therein, the wheel being engageable with the medicament pack sothat the recesses each receive a respective pocket.
 7. A deviceaccording to claim 6, wherein the index wheel and the lid driving meansare interconnected so that the rotation of one correlates with therotation of the other.
 8. A device according to claim 7, wherein theindex wheel and lid driving means are interconnected by a slippingclutch.
 9. A device according to claim 8, wherein the slipping clutchcomprises a first gear member which is movable with the index wheel andhas a toothed surface, and a second toothed gear member which is movablewith the lid driving means and has a toothed surface in meshingengagement with the toothed surface of the said first gear member, atleast one of the toothed surfaces having a toothed portion which ismovable back and forth with respect to the remainder of the toothedsurface of which it is part.
 10. A device according to claim 8, whereinthe slipping clutch comprises first clutch means movable with the indexwheel and second clutch means movable with the lid driving means, one ofthe clutch means comprising an annular array of serrations and the otherof the clutch means comprising means which grippingly engage theserrations when less than a predetermined force is applied between thetwo clutch means and which slip with respect to the serrations when aforce equal to or greater than the predetermined force is applied.
 11. Adevice according to claim 7, wherein the lid driving means comprises awheel on which the lid sheet is wound up, the said wheel having awinding surface which decreases in diameter when tension in the lidsheet increases.
 12. A device according to claim 11, wherein the saidwheel comprises a plurality of resiliently flexible arms each extendingtherefrom at an angle with respect to a radius.
 13. A device accordingto claim 4, comprising indexing means engageable between adjacentpockets to cause each pocket in turn to be positioned in communicationwith the outlet.
 14. A device according to claim 5, wherein the liddriving means comprises a pair of driving wheels which drivingly engagethe lid sheet between them.
 15. A device according to claim 14, whereinthe said driving wheels are toothed wheels having interengaging teeth.16. A device according to claim 4, comprising means for guiding the lidsheet and base sheet along separate paths at the opening station, thepaths reuniting downstream of the opening station, the said drivingmeans being located after the point where the paths reunite and beingoperable to drive both the lid sheet and base sheet.
 17. A deviceaccording to claim 16, wherein the said driving means comprises a pairof toothed wheels having interengaging teeth.
 18. A device according toclaim 4, comprising at least one chamber for receiving the elongatemedicament pack before opening, and for receiving the base sheet and lidsheet after peeling apart.
 19. A device according to claim 18, whereinthe elongate medicament pack and/or base sheet are held in coiled formby resilient coil-formers.
 20. A device according to claim 1, operablein a plurality of steps, which comprises indicator means adapted todisplay to a user an instruction as to the next step once the precedingstep has been taken.
 21. A device according to claim 20, wherein theindicator means comprises an indicator member which carries a pluralityof legends each constituting an instruction to the user, the indicatormember being movable by a given step being carried out to display thelegend relating to the next step.
 22. A medicament pack for use in aninhalation device, the pack comprising an elongate strip formed from abase sheet having a plurality of recesses spaced along its length and alid sheet hermetically but peelably sealed thereto to define a pluralityof containers, each container having therein inhalable medicament inpowder form.
 23. A medicament pack as claimed in claim 22, wherein thestrip is sufficiently flexible to be wound into a roll.
 24. A medicamentpack as claimed in claim 22, wherein the lid sheet and base sheet haveleading end portions which are not sealed to one another.
 25. Amedicament pack as claimed in claim 24, wherein at least one of the saidleading end portions is provided with means enabling it to be attachedto a winding means.
 26. A medicament pack as claimed in claim 22,wherein the hermetic seal between the base and lid sheets extends overtheir whole width.